The Actron Dwell Model 612 is a vintage-style automotive dwell tachometer used for measuring engine RPM and ignition dwell angle, essential for tuning points-based ignition systems. This unit is in like-new condition and comes in its original box. Exact dimensions are not available, but this is a handheld instrument typical of automotive diagnostic tools. Contents of the box are not fully specified; please verify included leads and instructions at time of purchase. A great find for classic car enthusiasts, mechanics, or hobbyists who work on older vehicles.